| 摘要 |
1294128 Light-polymerizable compositions W R GRACE & CO 10 Oct 1969 [11 Oct 1968 28 April 1969] 27833/72 Divided out of 1294127 Heading C3R A light-polymerizable composition comprises (a) a light-sensitive material consisting of (i) a polyene containing at least two reactive unsaturated carbon-carbon bonds per molecule and (ii) a polythiol containing at least two thiol groups per molecule, the total of carbon-carbon bonds per molecule and thiol groups per molecule being greater than four, (b) a photo-sensitizer and (c) from 1 to 25% of a pigment or from 0À1 to 25% of a dye, by weight of the composition. When exposed to light imagewise a coloured cross-linked polymer is obtained and, after removal of uncured material, a continuous tone solid image is formed. In examples the polyene is an allyl-terminated polymer (obtained from two polytetramethylene ether glycols, tolylene diisocyanate and allyl isocyanate), the polythiol is pentaerythritol tetrakis (#-mercaptopropionate), the photo-sensitizer is benzophenone and the compositions contain carbon black pigment and cyan, magenta and yellow dyes.
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